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physics604
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1. Two sides of a triangle are 4 m and 5 m in length and the angle between them is increasing at a rate of 0.06 rad/s. Find the rate at which the area of the triangle is increasing when the angle
between the sides of fixed length is [itex]\pi[/itex]/3.
$$A=\frac{xysinθ}{2}$$
Given:
$$\frac{dθ}{dt}=0.06$$ $$θ=\frac{\pi}{3}$$ $$x=4$$ $$y=5$$
Find: $$\frac{dA}{dt}$$
$$2A=xysinθ$$ $$2lnA=lnxysinθ$$ $$2\frac{1}{A}\frac{dA}{dt}=lnx+lny+lnsinθ$$
The problem now is that everything on the right cancels out, because x and y are constant, and the derivative sinθ is 0.
Am I doing this correctly? Where can I go from here?
between the sides of fixed length is [itex]\pi[/itex]/3.
Homework Equations
$$A=\frac{xysinθ}{2}$$
The Attempt at a Solution
Given:
$$\frac{dθ}{dt}=0.06$$ $$θ=\frac{\pi}{3}$$ $$x=4$$ $$y=5$$
Find: $$\frac{dA}{dt}$$
$$2A=xysinθ$$ $$2lnA=lnxysinθ$$ $$2\frac{1}{A}\frac{dA}{dt}=lnx+lny+lnsinθ$$
The problem now is that everything on the right cancels out, because x and y are constant, and the derivative sinθ is 0.
Am I doing this correctly? Where can I go from here?